KERRY WASHINGTON PLAYS ''BOX OF LIES'' WITH JIMMY FALLON TALKS MERMAID OBSESSION—WATCH NOW!

Who is a more convincing liar: Kerry Washington or Jimmy Fallon?

On Tuesday's Tonight Show, the Scandal star and late-night host tried to determine just that playing "Box of Lies." In the game, each player picks a box at random, sees what's inside, and without showing their opponent, describes the actual content or makes something up. It's up to the opponent to guess if they're telling the truth or fibbing.
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Kerry, 37, went first describing what was "in my box," telling Jimmy truthfully there was "a pumpkin with spaghetti in it!"She laughed as a very determined Jimmy tried to ascertain from her facial expressions whether she was telling the truth. Ultimately, though, he was wrong, guessing, "You lie!"

When it was his turn, the late-night host, 40, didn't have the best poker face when he tried to make up his box's contents! Although he really had a gold bead necklace with small troll dolls on it, he tried to convince the Scandal star he had an iPhone 6. Without missing a beat, Kerry asking, "Plus or regular?'Jimmy couldn't keep a straight face as he lied, "Plus," and rattled off a tale about "a figurine getting a tattoo from another figurine that I believe to be Justin Bieber That is what is in my box!"

Unsurprisingly, Kerry didn't fall for that one! Like Jimmy, though, the mother of one has a creative imagination. So much so, she revealed, that as a child, "I knew—I didn't say I thought—I knew that I was a mermaid."

"This is not a joke!" she insisted. "I was a mermaid—that's not a laugh line...I was a really good swimmer as a kid...and I was and I am still allergic to fish, so I had this theory that it was because I couldn't eat my brethren."

"But I'm more comfortable in water than I am on land," she said, adding laughingly, "and that's rare, especially for a black person...See! That is a stereotype, people, black people swim....Olivia Pope swims. Kerry Washington swims. That is my PSA for the night."

Jimmy joked with the Scandal star that for her next Tonight Show appearance, he'd bring in a tank of water so she could show off her mermaid skills. "I would prefer to do synchronized swimming," she said. "Will you do that?"

Guess we'll have to wait and see!

(E! and NBC are both part of the NBCUniversal family.)